md: use list_for_each_entry macro directly

The rdev_for_each macro defined in <linux/raid/md_k.h> is identical to
list_for_each_entry_safe, from <linux/list.h>, it should be defined to
use list_for_each_entry_safe, instead of reinventing the wheel.

But some calls to each_entry_safe don't really need a safe version,
just a direct list_for_each_entry is enough, this could save a temp
variable (tmp) in every function that used rdev_for_each.

In this patch, most rdev_for_each loops are replaced by list_for_each_entry,
totally save many tmp vars; and only in the other situations that will call
list_del to delete an entry, the safe version is used.

Signed-off-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 666b7ba47ec5..719943763391 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -215,7 +215,6 @@ static struct page *read_sb_page(mddev_t *mddev, long offset,
         /* choose a good rdev and read the page from there */
 
         mdk_rdev_t *rdev;
-        struct list_head *tmp;
         sector_t target;
 
         if (!page)
@@ -223,7 +222,7 @@ static struct page *read_sb_page(mddev_t *mddev, long offset,
         if (!page)
                 return ERR_PTR(-ENOMEM);
 
-        rdev_for_each(rdev, tmp, mddev) {
+        list_for_each_entry(rdev, &mddev->disks, same_set) {
                 if (! test_bit(In_sync, &rdev->flags)
                     || test_bit(Faulty, &rdev->flags))
                         continue;